Multi-leaved Cultivars
There are some cultivars of white clover (Trifolium repens) which regularly produce more than three leaflets, including purple-leaved T. repens 'Purpurascens Quadrifolium' and green-leaved T. repens 'Quadrifolium'.
Trifolium repens 'Good Luck' is a cultivar which has three, four, or five green, dark-centered leaflets per leaf.
Read more about this topic: Four-leaf Clover